


Thermoregulation

by Fightmethensonnyboi



Category: Katekyou Hitman Reborn!
Genre: Abandonment, Abuse, Angst, BAMF Sawada Tsunayoshi, Found Family, Hacker Tsuna, M/M, Mentions of Suicide, Mutual Pining, Reborn - Freeform, Romance, Strong Tsuna, Twin Fic, everybody loves Tsuna, mabye all27?, violance
Language: English
Status: In-Progress
Published: 2020-10-01
Updated: 2020-10-07
Packaged: 2021-03-08 01:55:51
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,796
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26757616
Author URL: https://archiveofourown.org/users/Fightmethensonnyboi/pseuds/Fightmethensonnyboi
Summary: Ietsuna had always been favoured over his older brother, Tsunayoshi, his grades were better, he was popular- he was everything Tsuna wasn't. and Tsuna was fine with that really,  he should feel lucky that he had a roof over his head, even if he rarely feels happy anymore. at least he was good with computers,  even if his activities were... let's say less than legal?he does wonder sometimes though, what it would be like to have a real family.
Relationships: Hibari Kyouya/Sawada Tsunayoshi
Comments: 5
Kudos: 120





	1. The beginning

**Author's Note:**

> Prynhawn da pawb!  
> This is a rewrite of my cringy 14 year old me story from wattpad, which i was hoping to never look at again, but some people liked t?? it's ranked at like 80th in harem? which is strange because i didn’t even get to the romance part when i wrote it, but honestly? tsuna needs all the love so i might make this an All27 fic if ya'll want? cause that would be dope af.
> 
> I hope you enjoy!

  
  
  
Tsuna woke up with a start as the insistent chiming of the alarm clock rang throughout the room. His tired chocolatey eyes shot open, still blurry from sleep as he fumbled and groaned, trying to turn the damn thing off!

he succeeds with a triumphant huff as he clicks the clock off rubbing his eyes as he swings his legs off the bed and gets dressed quickly, shoving a breakfast bar in his mouth and stuffing his laptop into his bag, he places his head to the floor and waits a minute before nodding to himself.  
aremoving the fake ceiling panel he drops his bag towards the bed. down in his "bedroom" he hears it land with a thunk, before following it by landing on a strategically placed pillow.

' _stuck the landing_!' he smiles to himself as he quietly makes his way from his room to the hallway, looking both ways and listening out for any movement. he holds the handrail as he descends the stairs, the house eerily quiet, looking out for either his brother or his mother, he would have made it too if it weren't for the strangely dressed baby wearing a fedora.

' _what the actual hell?!'_ Tsuna screamed internally as the baby smoothly looked him up and down before seemingly pinning him in place with his onyx black eyes. "Ciaosu" spoke the child in a high pitched voice, that made Tsuna cringe internally. "I'm the home tutor Reborn" he gazed up at Tsuna expectantly as if there was an appropriate answer for this...situation.   
Tsuna just kinda- nodded politely and gave an awkward thumbs up as he stepped aside to let the kid- reborn inside. who the hell would leave a kid outside by himself?? not Tsuna thats for sure.

he led the kid to the kitchen where he filled up the kettle with water, (figuring he had time before nana came downstairs) and rooted around for the coffee before pausing midway, ' _why the hell am i giving coffee to a baby_??' he shakes his head and looks over his shoulder to see reborn looking very intently at him. a shiver goes down his spine and the hair on the back of his neck rises, ' _for some reason_ ' he thinks ' _i should stay the hell away from this kid'._ the brunette turns around slowly, keeping his eyes on the home tutor as he walks once more to the door, the other occupant of the room looking at his every step.

the boy smiles tightly as the silence turns thick with an uncomfortable tension, not a word exchanged between them as he waves slightly and walks toward the front door again, sweat dampening his skin as he hears movement from upstairs, he runs the rest of the way to the door as he hears Ietsuna's heavy footfalls on the stairs and is out the house before anything more surprising can happen again.

\--------------------------------------------

The feeling of danger didn't fade as he walked to school, his heartbeat was elevated the entire time. he just had a feeling that something... not bad but not good was going to happen. he was proven right when just before he got to the gate he had the sudden urge to duck. Tsuna hit the floor just in time as a brick hit the air where his head was, scrambling upwards he swung around to face his brother??

Ietsuna's muddy brown eyes were now seemingly glowing with a yellow light his face scrunched up in an expression of indescribable rage, what was surprising ,though was the fact that he was only in his underwear and had a weak orange flame flaring on his forehead. "Reborn!" he roared " Teach Dame-Tsuna a lesson!" he began running almost inhumanly fast towards Tsuna, who squeaked and began to sprit the home stretch to the gate,

fear pounding through his body, his vision was blurry as he pushed his way through the crowd of students who had stopped to watch, he tripped on the brick that was thrown before, launching him flat on his face, the gravel tearing at his skin as his brother caught up to him.

Ietsuna grabbed on to his ankle with a bruising grip as he attempted to drag Tsuna away from the school. The brunete breathed heavily, with tears in his eyes as he tried to kick his brother away, managing to get a good kick to his solar plexus, loosening his attackers grip and allowing him to get away. He limped as quick as he could over to the trees surrounding the entrance, his ankle was throbbing as he ran around the tree, and waited.

he sat there shaking until he heard the muffled shrieking that usually signified the disciplinary committee. Tsuna blushed suddenly as he peered around his hiding spot to catch a glimpse of the legendary demon prefect and head of the disciplinary committee.

Hibari Kyoya stood there, in all his _terrifying_ glory with his hand clamped onto Ietsuna's head, his gunmetal Gray eyes gleaming as he looked to where Tsuna was hiding. Tsuna squeaked when the elder made a beckoning gesture towards him. He quickly limped towards the prefect, not noticing the deepening frown on Hibari's face when his stare met his leg.

By now the weird fire stuff that was on Ietsunas head had gone out and he was instead glaring at Tsuna like he'd kicked his puppy. Hibari glanced at his expression and looked again at Tsuna.

"herbivore, explain" he ordered calmly.

Tsuna stared helplessly at the prefect, his cheeks still dusted red and he scratched at his head, trying to come up with an explanation.

"Apologies, chairman that would be my fault" Tsuna started as he glanced down to see reborn, who was gazing fearlessly at the upperclassman. Tsuna was shocked, and then worried as he couldn't predict Hibari's reaction so he shuffled lightly in front of the toddler, just in case.

This did not go unnoticed by reborn or Hibari, who both gave him an unreadable look. Tsunas hands tangled up in his shirt in anxiety but didn't move. Reborn looked once more at Ietsuna who was pouting "lets call this an experiment gone wrong" his eyes flicked to the prefect who was still looking at Tsuna, whose cheeks were steadily glowing redder by the second to the prefects utter confusion.

He looked back to the baby "Ensure that this does not happen again" he says monotonously "And head to you classrooms as soon as possible" he looked pointedly at the siblings before turning and walking away.

said siblings immediately did as ordered, Ietsuna running off to find some clothes and the brunette hobbling off to his classroom before the final bell rang.

reborn who'd been left in the dust kneaded his forehead with his small palms, just what the hell had Iemitsu dropped him in? first, the information he'd been given mentioned _nothing_ about a sibling- _an older sibling at that_ and secondly that there was _apparently_ some huge family drama that they didn't acknowledge??

reborn sighed as Leon morphed into a phone and he rang a familiar number.

he was going to get to the bottom of this. _ **Now.**_


	2. Tsuna's the only one with a braincell (Pity its just the one)

**Summary for the Chapter:**

> they also have some…interesting recruitment tactics.
> 
> SL: Such as?
> 
> VS: Why pamphlets of course Hibari-san.
> 
> SL: Just send me the file, or I’ll hunt you down.
> 
> Skylark has left the chatroom.
> 
> VS: …I- I wasn’t joking about the pamphlets?

**Notes for the Chapter:**

> BORE DA!  
> Ryohei is here! My sweet summer boy! i've decided to make this an all27 fic, just because i'm multishipper trash and I love Tsuna!  
> Comment your favourite ship or visit my tumblr in the end notes and we can talk about it!
> 
> I hope you enjoy!

Tsuna spent the rest of the day attending classes and hiding from his tormentors, who were basically _everywhere_.when the bell rung he was always the first out of class, though he was slower today which meant the bully’s had nearly caught up to him, luckily tuna was used to this so he managed to hide in an empty classroom before they could find him.

After the pursuit was over, he made his way towards the very _very_ back of the school, away from the main buildings and towards a wooden, overgrown, _decrepit_ equipment shed. Passing the still strangely sturdy entrance he heads around the left side of the shack humming under his breath he pokes at a loose wooden panel, ensuring that it wasn't stuck again, before he crawls inside.

The inside was just as disappointing as the outside, a few mouldy gym matts and some broken volleyball nets, it also _stank_ of dust and neglect.

_‘Same’_ thought Tsuna suddenly, huffing a laugh as he hauled out his battered laptop and placed it on his lap.

The light of the laptop illuminated the tired brunettes face as he gathered the relevant documents and videos and then placed them neatly into an encrypted folder.

With a sigh, he gets to work.

**Ventisette has entered the chatroom**.

_VS: The Gokiburi yakuza is planning on “taking over” Namimori again_.

**Skylark has entered the chatroom.**

_ SL: Tell me. _

_ VS: Of course Hibari-san, according to what i found out, they have purchased a warehouse on the outskirts of Namimori’s shopping district, based on their resent purchases and emails, they are planning on taking over and extorting money from the locally owned stores before moving onto the bigger stores. they also have some…interesting recruitment tactics. _

_ SL: Such as? _

_ VS: Why pamphlets of course Hibari-san. _

_ SL: Just send me the file, or I’ll hunt you down. _

**Skylark has left the chatroom.**

_ VS: …I- I wasn’t joking about the pamphlets? _

Tsuna giggled lightly to himself, feeling his cheeks warm once more as he sent the folder. If he had friends he wonders, they would probably be a little concerned about his strange admiration of the demonic prefect. He was just so…strong? Dedicated? Devoted? _Ridiculously handsome?_ Then again if he had friends they'd also probably be concerned about his Anonymous hacking.

He quickly shook himself of these thoughts as he looked at the time, figuring he had enough until the end of the day, he checked on his ankle.

Tsuna had been injured by his brother before obviously, but he'd been getting better at avoiding him lately, until today really.

He looked somewhat disgruntled as he poked at the purple swelling on his foot, the circumference of his ankle was now roughly that of a baseball on _steroids_ and was throbbing painfully in time with his heartbeat. This wasn't the worst he'd gotten, but it would probably be one of the most painful. Grimacing he looked around to where he'd hidden the compression tape, rustling around in the gap between the matts under him. He finds it with a huff of triumph a goofy smile on his face as he begins to wrap his foot, not too tightly to cut off the blood flow, but enough to support him until he got back to the house.

He was almost done when he heard cheering from the nearby gymnasium. Tsuna felt his face scrunch in confusion, it was the end of the day why were there people gathering at the gym?

He shuffles over to the entrance, careful not to alert anyone inside, he peeks through the gap between the wall and the door.

Mochida stood in his full kendo gear on one side of the court, Shinai held proudly over his shoulder, what seemed like the entire school cheering his name behind him. Across from him is an irate Ietsuna who already had Kotei gloves on and was equipped with his own Shinai.

Mochida smirks, “ I cant _wait_ until I win and Kyoto will belong to me!” His friends Cheer his name from the sidelines “ I also cant believe you’re still trying to get with her, with a family like _yours?_ I'm surprised she doesn't run for the hills!”

Ietsuna scoffs “ you think you could make her happy? all you do is bully middle schoolers, hell you’re so scummy _you tried to give me weighted gloves!_ ”

Sensing that the back and forth wasn’t that important, the brunette scans the area for Kyoko. she stood near Hana, her face shadowed as she gripped her friends hand in a vice like hold, but Hana? oh Hana looked _enraged,_ but her shouts where drowned out by the crowd, her free hand rubbing frantic circles on the smaller girls hand.

This entire situation looked like it was upsetting Kyoko, which? if the idiots _truly_ liked her they never would have done in the first place. Scoffing slightly Tsuna turned away from the drama unfolding in front of him and headed towards the only person who could fix this mess.

As it was the end of the day at this point Tsuna found Ryohei Sasagawa at the front entrance, probably waiting for his sister. When the senior spotted him he yelled “Ah the little Sawada? how _extremely_ convenient!! have you seen Kyoko anywhere?” He grinned brightly and Tsuna just _had_ to smile helplessly. Out of all the people in the school, neither Sasagawa sibling had ever caused him trouble, or aided his tormentors in any way- even frowned upon it in some circumstances.

Tsuna nodded and beckoned Ryohei to follow him heading quickly towards the gym. The light haired senior followed along at a slower pace, his confusion very apparent as he hurried after the younger boy.

Both boys were panting slightly as they reached the building, and from the noise leaking from the doors, it seemed like yer fight had started. Ryohei looked startled, his brow furrowing as he rushed through the doors with a loud **_bang!_**

The cheering went silent, the only noise from the room being from the boys fighting in the centre of the hall, completely oblivious as they scrapped at each other, weapons long since discarded at this point.

“kyoko! Where are you?” Ryohei shouted “this is _extremely_ strange?” Tsuna watched as Kyoko emerged from the crowd, face still shadowed as she rushed to her brother, Hana's hand still held tight in her grasp.

She crashed into her brothers chest, his muscled arms coming around her in an instinctive move, “kyoko? he questions confusedly, a concerned expression clouding his face.

“Onii-San…” her voice emerged, thick and ragged. Her face lifted and it was obvious she’d been crying, her amber eyes were red and puffy and her face wet with tears.

Ryohei quickly turned angry, clutching tighter to his sister, he turned to Hana who was rubbing her friends back, “ These _stupid fucking monkeys_ thought it was a grand idea, to fight over who should date Kyoko, without thinking about what she wanted!” the girl spat out flinging her hand to where Ietsuna and Mochida were rolling around on the floor.

Ryohei scowled “ but aren’t you two, like- ... _y’know?_ ” he trailed off.

Hana rolled her eyes “yeah we are, but try telling that to those two- ' _chad's_ ' over there!” she grabbed Kyoko’s hand once more guiding her into her arms instead and stroking her strawberry blonde hair gently as she sobbed.

Tsuna’s eyes widened from outside the gym- an imaginary lightbulb appearing over his head.

_‘Ahhh…that would explain a lot’_ he thought as he looked at Hana being protective over Kyoko, smiling slightly as he noticed the other girls calm down in her _girlfriends_ embrace.

_‘good for them!’_ He thought happily, his eyes shined and he clapped his hands together quietly, they really were well matched!.

Royhei on the other hand stormed over to where the boys were winding down from the fight, fists bloody and sweaty and Ietsuna had a _bite mark_ on his forehead? weird.

The normally sunny senior grabbed both of the children by their collars, _like little cubs_ , their feet hovering inches off the floor as they squirmed and protested.

…That was until they saw who was holding them.

Ryohei grinned sharply and his grey eyes sparkled as he beheld their pale faces, Mochida was trembling in fear while Tsuna’s brother looked like he was pretending like he _wasn't_ about to shit himself. (he was failing)

“If you wanted to join the boxing team so badly you could have just said so!” Ryohei said jovially, his tanned features shadowed by the florescent gym lights. He turned around abruptly and began dragging the idiots behind him, heading towards the exit, smile still present on his face as he said “ Hell, we can begin training right now? I hope that little scuffle got you _extremely_ warmed up!” He roared enthusiastically marching happily towards the boxing club.

The boys were so distracted, screaming at each other and trying to escape the boxers grip, that they didn't notice the bright grin and grateful wink that Ryohei sent towards Tsuna as he passed.

Tsuna blushed shyly before he hid once more as the rest of the students left the gym, still buzzing with gossip from the event that just happened, Tsuna managed to keep quiet as Hana and Kyoko emerged hand in hand the lighter haired girl giggling at something the other had said.

Tsuna felt his face lift in a rare, genuine smile, happy that he could be of help.

Meanwhile somewhere above him a well dressed toddler tapped a thin looking file against his hand thoughtfully.

**Notes for the Chapter:**

> hey! come talk to me at https://www.tumblr.com/blog/view/foxybusiness !

**Author's Note:**

> yo so this is up on wattpad @hichiichi if you wanna know 👀


End file.
